Organic light emitting diode display device and method of manufacturing the same

ABSTRACT

The OLED display device includes a substrate, a first electrode located on the substrate, a pixel defining layer located on the first electrode to expose a part of the first electrode, a fluorine-based polymer layer located on the pixel defining layer, an organic layer located on the first electrode, and a second electrode located on the entire surface of the substrate. The method of manufacturing the OLED display device includes forming a first electrode on a substrate, forming a pixel defining layer on the first electrode, forming a fluorine-based polymer layer on the pixel defining layer, patterning the fluorine-based polymer layer and the pixel defining layer by laser ablation to open a part of the first electrode, forming an organic layer on the opened first electrode, and forming a second electrode on the entire surface of the substrate.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of Korean Patent Application No.2008-104427, filed Oct. 23, 2008, the disclosure of which is herebyincorporated herein by reference in its entirety.

BACKGROUND

1. Field

Non-limiting example embodiments of the present invention relate to anorganic light emitting diode (OLED) display device and methods ofmanufacturing the same, and more particularly, to OLED display devicesin which an organic layer is formed after easily patterning a pixeldefining layer formed of a photoresist material using a fluorine-basedpolymer layer to improve a surface property of a first electrode, and amethod of manufacturing the same.

2. Related Art

Among flat panel display devices, an OLED display device has advantagessuch as a fast response time of 1 ms or less, low power consumption,self-emission and a wide viewing angle as a moving picture displaymedium regardless of its size. It may be also fabricated at a lowtemperature and in a simple process based on conventional semiconductorprocessing technology, and thus attracts attention as a next generationflat panel display device.

The OLED display device may be classified as a polymer devicemanufactured by using a wet process or a small molecule devicemanufactured by using deposition, depending on the material used for anorganic light emitting diode and the process.

Among methods of patterning a polymer or small molecule emission layer,when an emission layer is pattered by ink-jet printing, materials fororganic layers except for an emission layer are limited, and a structurefor ink-jet printing should be formed on a substrate. When an emissionlayer is pattered by deposition, it is difficult to fabricate a largedevice due to use of a metal mask. An alternative technique for such apatterning technique is laser induced thermal imaging (LITI), which hasdeveloped in recent times.

However, there are some problems when an organic layer including anemission layer is formed by these methods. An organic light emittingdiode includes many underlying polymer organic layers, which may be alsoformed in a non-emission region while these organic layers including anorganic emission layer are formed on a first electrode, therebyaffecting an underlying device. Thus, defects may be generated andproduction yield may be reduced.

SUMMARY

Non-limiting example embodiments of the present invention provideorganic light emitting diode (OLED) display devices. The organic lightemitting diode display device may include a substrate, a firstelectrode, a pixel defining layer, a fluorine-based polymer layer, anorganic layer and a second electrode. For example, the first electrodeis located on the substrate. The pixel defining layer is located on thefirst electrode. The pixel defining layer has an opening. Thefluorine-based polymer layer is located on the pixel defining layer. Thefluorine-based polymer has an opening. The opening of the fluorine-basedpolymer layer interconnects to the opening of the pixel-defining layerto expose a part of the first electrode. The organic layer is located onthe exposed part of the first electrode. The second electrode is locatedon the organic layer and the fluorine-based polymer layer.

Non-limiting example embodiments of the present invention provide OLEDdevices. The OLED devices include a substrate, a first electrode, apixel, a fluorine-based polymer layer, an organic layer and a secondelectrode. For example, the first electrode is located on the substrate.The pixel defining layer is located on the first electrode. The pixeldefining layer has an opening. The pixel defining layer is formed usinga photoresist material. The fluorine-based polymer layer is located onthe pixel defining layer. The fluorine-based polymer has an opening. Theopening of the fluorine-based polymer layer interconnects to the openingof the pixel-defining layer to expose a part of the first electrode. Theorganic layer is located on the exposed part of the first electrode. Thesecond electrode is located on the organic layer and the fluorine-basedpolymer layer. The fluorine-based polymer layer comprises at least oneof the compounds represented by Formulae 1 to 3:

-   -   wherein n is an integer of about 50 to 1,000;

-   -   wherein m is an integer of about 50 to 1,000, and n is an        integer of about 50 to 1,000; and

-   -   wherein n is an integer of about 50 to 1,000.

Non-limiting example embodiments of the present invention providemethods of manufacturing OLED devices. For example, a substrate isprovided. A first electrode is formed on the substrate. A pixel defininglayer is formed on the first electrode. A fluorine-based polymer layeris formed on the pixel defining layer. An opening is formed in the pixeldefining layer and the fluorine-based polymer layer to expose a part ofthe first electrode. An organic layer is formed on the exposed part ofthe first electrode. A second electrode is formed on the organic layerand the fluorine-based polymer layer.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the invention, and many of the attendantadvantages thereof, will be readily apparent as the same becomes betterunderstood by reference to the following detailed description whenconsidered in conjunction with the accompanying drawings in which likereference symbols indicate the same or similar components, wherein:

FIGS. 1A to 1E are cross-sectional views illustrating an organic lightemitting diode (OLED) display device according to non-limiting exampleembodiments of the present invention.

DETAILED DESCRIPTION

Non-limiting example embodiments of the present invention will bedescribed more fully hereinafter with reference to the accompanyingdrawings, in which the non-limiting example embodiments of the inventionare shown. This invention may, however, be embodied in different formsand should not be construed as limited to the embodiments set forthherein. Rather, these non-limiting embodiments are provided so that thisdisclosure will be thorough and complete, and will fully convey thescope of the invention to those skilled in the art. In the drawings, thethicknesses of layers and regions may be exaggerated for clarity. Likereference numerals designate like elements throughout the specification.

FIGS. 1A to 1E are cross-sectional views illustrating an organic lightemitting diode (OLED) display device according to non-limiting exampleembodiments of the present invention.

Referring to FIGS. 1A and 1B, a substrate 100 is provided. The exemplarymaterial included in the substrate 100 may be glass or plastic.

Subsequently, a buffer layer 101 is formed on the substrate 100. Thebuffer layer 101 functions to facilitate crystallization of apolycrystalline silicon layer to be formed in the following process bypreventing diffusion of moisture or impurities generated from theunderlying substrate 100 and/or controlling a heat transfer rate duringcrystallization.

Then, an amorphous silicon layer (not illustrated) is formed on thebuffer layer 101. Here, the amorphous silicon layer may be formed bychemical vapor deposition or physical vapor deposition. While or afterforming the amorphous silicon layer, the amorphous silicon layer may bedehydrogenated to reduce the concentration of hydrogen.

A semiconductor layer 102 is formed by crystallizing the amorphoussilicon layer into a polycrystalline silicon layer. Here, thesemiconductor layer 102 is formed by crystallizing the amorphous siliconlayer using a solid phase crystallization (SPC) process, a sequentiallateral solidification (SLS) process, a metal induced crystallization(MIC) process, a metal induced lateral crystallization (MILC) process, asuper grain silicon (SGS) process, a rapid thermal annealing (RTA)process, or an excimer laser annealing (ELA) process, and thenpatterning the crystallized layer.

After that, a gate insulating layer 104 is formed on the substrate 100having the semiconductor layer 102, and the gate insulating layer may beformed using silicon oxide, silicon nitride or a combination thereof. Inaddition, the gate insulating layer may be a single- or multi-layeredstructure.

A gate electrode 106 is then formed on the gate insulating layer 104.The gate electrode 106 is formed on a portion of the gate insulatinglayer 104 corresponding to the semiconductor layer 102 by forming ametal layer, and etching the metal layer for the gate electrode byphotolithography. The metal layer for a gate electrode (not illustrated)may be a single layer of aluminum (Al) or an aluminum-neodymium (Al—Nd)or a multilayer including an aluminum alloy stacked on a chromium (Cr)or molybdenum (Mo) alloy.

Referring to FIG. 1B, source and drain regions 102 s and 102 d areformed by injecting an impurity having an opposite conductivity type tothe impurity injected into the silicon layer into the source and drainregions 102 s and 102 d of the semiconductor layer 102, using the gateelectrode 106 as a mask. Alternatively, the source and drain regions maybe formed by forming a photoresist pattern exposing the regions to besource and drain regions and then injecting an impurity. When the gateelectrode 106 is formed at a location corresponding to the semiconductorlayer 102, channel, source and drain regions 102 c, 102 s and 102 d maybe defined in the semiconductor layer 102 as descried in the followingprocess.

Afterward, an interlayer insulating layer 108 is formed on the entiresurface of the substrate 100. The interlayer insulating layer 108 may bea silicon nitride layer, a silicon oxide layer or a multilayer thereof.

Subsequently, source and drain electrodes 110 a and 110 b connected tothe source and drain regions 102 s and 102 d through contact holes (notillustrated) exposing the source and drain regions 102 s and 102 d ofthe semiconductor layer 102 are formed by etching the interlayerinsulating layer 108 and the gate insulating layer 104. The source anddrain electrodes 110 a and 110 b may be formed using material such asMo, Cr, tungsten (W), Al—Nd, titanium (Ti), MoW and Al. These may beused alone or in a combination thereof.

Referring to FIG. 1C, a passivation layer 110 is formed on the entiresurface of the substrate including the source and drain electrodes 110 aand 110 b, and a planarization layer 111 is formed on the passivationlayer 110. A first electrode 112 connected to one of the source anddrain electrodes 110 a and 110 b through a via hole 111 a formed in theplanarization layer 111 is then formed. The first electrode 112 may be atransparent or reflective electrode. When the first electrode 112 isused as a transparent electrode, the first electrode 112 may includeITO, IZO, ZnO or In₂O₃. These may be used alone or in a combinationthereof. In contrary, when the first electrode 112 is used as areflective electrode, the first electrode 112 may be formed in amultilayered structure including a first layer formed including Ag, Mg,Al, Pt, Pd, Au, Ni, Nd, Ir, Cr or a combination thereof, and a secondlayer including ITO, IZO, ZnO or In₂O₃ on the first layer.

After that, a pixel defining layer 114 defining a pixel is formed on thefirst electrode 112. Here, the pixel defining layer 114 is formed usinga photoresist material, and formed to have a thickness of about 1,000 Åto 1 μm for proper function.

A polymer layer 115 is formed on the pixel defining layer 114.

Here, the polymer layer 115 may be formed using a fluorine-based polymerselected from materials represented by Formulae 1 to 3. Alternatively,the polymer layer 115 may be formed using a functional materialcontaining about 10 to 50% fluorine.

(Here, n is an integer of about 50 to 1,000.)

(Here, m is an integer of about 50 to 1,000, and n is an integer ofabout 50 to 1,000.)

(Here, N is an Integer of about 50 to 1,000.)

When the polymer layer 115 is formed using the fluorine-based polymer,the polymer layer 115 may have a coating effect of a hydrophobicsurface. Thus, diffusion of water, organic materials or othercontaminants may be prevented. The fluorine-based polymer layer 115 maybe advantageously formed to have a thickness of about 100 Å or more forthe coating effect. However, when the polymer layer 115 is too thick, itis difficult to apply laser ablation to the polymer layer. Thus, thepolymer layer 115 may be advantageously formed to have a thickness ofabout 3,000 Å or less, and the polymer layer may be formed by depositionor spin coating.

Referring to FIG. 1D, pulse-type excimer laser is applied to a part ofthe polymer layer 115 to partially remove the pixel defining layer 114and the polymer layer 115 by laser ablation, thereby exposing a part ofthe first electrode 112.

When the laser ablation is applied to the polymer layer 115 by radiatingthe excimer laser, the laser is transmitted through the polymer layer115, and is absorbed in the pixel defining layer 114 formed using aphotoresist at the laser-irradiated portion, thereby lifting off thephotoresist due to thermal diffusion. Thus, the polymer layer 115 andthe pixel defining layer 114 are patterned. Here, when the laser isirradiated at an intensity of about 300 mW/cm² or more, the photoresistbecomes hydrophilic, and thus is easily lifted off.

The surface of the first electrode 112 opened by patterning ishydrophilic, so that the first electrode 112 may have a better surfaceproperty when an organic layer is formed.

Referring to FIG. 1E, an organic layer 116 including an organic emissionlayer is formed on the opened first electrode 112. The organic layer 116may be formed by deposition or laser induced thermal imaging (LITI).

A second electrode 118 is then formed on the entire surface of thesubstrate 100.

Here, the second electrode 118 may also be a transparent or reflectiveelectrode. When the second electrode 118 is a transparent electrode, thesecond electrode 118 may include a first layer formed using Li, Ca,LiF/Ca, LiF/AI, Al, Mg or a combination thereof and a second layerformed using ITO, IZO, ZnO or In₂O₃ on the first layer. Here, the secondlayer may be an auxiliary electrode or a bus electrode line.

Alternatively, when the second electrode 118 is a reflective electrode,the second electrode 118 may be formed using Li, Ca, LiF/Ca, LiF/AI, Al,Mg or a combination thereof on the entire surface of the substrate.

The organic layer 116 located between the first and second electrodes112 and 118 may be formed using a small molecule or polymer organicmaterial.

The thin film transistors may be flexibly manufactured, and thus theOLED display device including the thin film transistor may haveflexibility.

According to an OLED display device and a method of manufacturing thesame of the present invention, a fluorine-based polymer layer is formedon a pixel defining layer to prevent diffusion of contaminants such asorganic materials and water, and thus defects generated in fabricationof the OLED display device may be reduced, a process may be simplifieddue to an easy patterning technique and production yield may beeffectively improved.

Although the present invention has been described with reference tonon-limiting example embodiments thereof, it will be understood by thoseskilled in the art that a variety of modifications and variations may bemade to the present invention without departing from the spirit or scopeof the present invention defined in the appended claims, and theirequivalents.

1. An organic light emitting diode (OLED) display device, comprising: asubstrate; a first electrode located on the substrate; a pixel defininglayer located on the first electrode, the pixel defining layer having anopening; a fluorine-based polymer layer located on the pixel defininglayer, the fluorine-based polymer layer having an opening, the openingof the fluorine-based polymer layer interconnecting to the opening ofthe pixel-defining layer to expose a part of the first electrode; anorganic layer located on the exposed part of the first electrode; and asecond electrode located on the organic layer and the fluorine-basedpolymer layer.
 2. The OLED display device of claim 1, wherein thefluorine-based polymer layer is formed using a hydrophobic material. 3.The OLED display device of claim 1, wherein the fluorine-based polymerlayer comprises at least one of the compounds represented by Formulae 1to 3:

wherein n is an integer of about 50 to 1,000;

wherein m is an integer of about 50 to 1,000, and n is an integer ofabout 50 to 1,000; and

wherein n is an integer of about 50 to 1,000.
 4. The OLED display deviceof claim 1, wherein the fluorine-based polymer layer comprises acompound represented by Formula 1:

wherein n is an integer of about 50 to 1,000.
 5. The OLED display deviceof claim 1, wherein the fluorine-based polymer layer comprises acompound represented by Formula 2:

wherein m is an integer of about 50 to 1,000, and n is an integer ofabout 50 to 1,000.
 6. The OLED display device of claim 1, wherein thefluorine-based polymer layer comprises a compound represented by Formula3:

wherein n is an integer of about 50 to 1,000.
 7. The OLED display deviceof claim 1, wherein the fluorine-based polymer layer has a thickness ofabout 100 to 3,000 Å.
 8. The OLED display device of claim 1, wherein thepixel defining layer is formed using a photoresist material.
 9. The OLEDdisplay device of claim 1, wherein the pixel defining layer has athickness of about 1,000 Å to 1 μm.
 10. An organic light emitting diode(OLED) display device, comprising: a substrate; a first electrodelocated on the substrate; a pixel defining layer located on the firstelectrode, the pixel defining layer having an opening, the pixeldefining layer formed using a photoresist material; a fluorine-basedpolymer layer located on the pixel defining layer, the fluorine-basedpolymer layer having an opening, the opening of the fluorine-basedpolymer layer interconnecting to the opening of the pixel-defining layerto expose a part of the first electrode, the fluorine-based polymerlayer comprising at least one of the compounds represented by Formulae 1to 3:

wherein n is an integer of about 50 to 1,000;

wherein m is an integer of about 50 to 1,000, and n is an integer ofabout 50 to 1,000; and

wherein n is an integer of about 50 to 1,000; an organic layer locatedon the exposed part of the first electrode; and a second electrodelocated on the organic layer and the fluorine-based polymer layer.
 11. Amethod of manufacturing an organic light emitting diode (OLED) displaydevice, comprising: providing a substrate; forming a first electrode onthe substrate; forming a pixel defining layer on the first electrode;forming a fluorine-based polymer layer on the pixel defining layer;forming an opening in the pixel defining layer and the fluorine-basedpolymer layer to expose a part of the first electrode; forming anorganic layer on the exposed part of the first electrode; and forming asecond electrode on the organic layer and the fluorine-based polymerlayer.
 12. The method of claim 11, wherein the formation of the openingin the pixel defining layer and the fluorine-based polymer layercomprises patterning the pixel defining layer and the fluorine-basedpolymer layer by laser ablation.
 13. The method of claim 12, wherein thelaser is irradiated at an intensity of about 300 mW/cm² or more.
 14. Themethod of claim 11, wherein the pixel defining layer is formed using aphotoresist material.
 15. The method of claim 11, wherein thefluorine-based polymer layer is formed using at least one of thecompounds represented by Formulae 1 to 3:

wherein n is an integer of about 50 to 1,000;

wherein m is an integer of about 50 to 1,000, and n is an integer ofabout 50 to 1,000; and

wherein n is an integer of about 50 to 1,000.
 16. The method of claim15, wherein the fluorine-based polymer layer comprises a compoundrepresented by Formula
 1. 17. The method of claim 15, wherein thefluorine-based polymer layer comprises a compound represented by Formula2.
 18. The method of claim 15, wherein the fluorine-based polymer layercomprises a compound represented by Formula
 3. 19. The method of claim11, wherein the fluorine-based polymer layer is formed to have athickness of about 100 to 3,000 Å.